In liquid crystal display devices, a reflective film, one of optical films, is disposed for a light-guiding plate on the side thereof opposite to (on the rear surface side of) a liquid crystal cell. The reflective film plays a role in reflecting light emitted from the light-guiding plate to the rear surface side to return the light to the viewer side (recycling the light). Color filters are used in emission of light beams of colors. The color filter absorbs the light beams out of a predetermined wavelength region, thereby exhibiting a function to emit the light beam of a color to be emitted from pixels from the pixels.
A further improvement in luminance and an increase in saturation, which means that the width of distribution of wavelengths of the light beams emitted from the pixels of the respective colors is narrowed to emit intense light beams of purer colors, are required for the liquid crystal display devices.
The conventional reflective film is produced by coating a metal plate with a light-diffusing coating, as described in Patent Literature 1. The reflectance of the reflective film varies between approximately 90% and 93% at a wavelength of 550 nm depending on the material of the light-diffusing coating. The conventional reflective films reflect all visible light beams almost equally, and look white to human eyes. In such a reflective film, the reflectance is essentially in a broad band (the reflecting light beams are distributed across a wide wavelength range). For this reason, the reflective film is not used for the increase in saturation.
Patent Literature 2 proposes a wavelength-selective reflective filter including a fluorescent layer that recycles light beams having a wavelength that do not transmit through a color filter and are absorbed to be lost. However, the fluorescent layer only converts the light at a short wavelength into the light at a longer wavelength; if the wavelength range of a light source is wide, there has been a problem that red light or green light is produced more than needed. For this reason, the wavelength-selective reflective filter including the fluorescent layer loses the color balance of a typical display device.